Is it normal for your 6-year-old stepdaughter not to wipe her own bottom when she uses the potty if she is in first grade?

No it isn't normal, but with your patience you can teach her. It's extremely important that she learn to wipe herself properly or she will have one infection after the other. Since this is your step-daughter it appears to me she has some emotional problems and when he and his wife weren't getting along this young girl was probably never taught how to wipe herself properly. It may not be you personally she is upset with, but missing her own mother. When parents split-up kids only see one thing "mom and dad". Many times children often blame themselves for their parent's split-up and it really upsets me to hear children say something like, "If only I had not been so naughty, mom/dad would still be together." Many parents that don't get along are often so enraged at each other they often forget about the children's feelings and try to keep it private. Children know! I suggest you have an evening alone with her. Perhaps her favorite video, both of you get into your nighties and "pig out" on all sorts of goodies. Keep the evening light and then slowly and very carefully try to find out what emotional drawbacks she is feeling. Remember, a 6 year old doesn't even realize they are "acting out" because they are angry or upset. You might get lucky and find out just how she was treated at home with her biological mother. NEVER giver her heck for not wiping herself. Go on with your day and act normal. This won't last forever. Good luck Marcy